Tricks For English Sentence completion

Word Fitting:

Before You Look At The Answer-Choices, Think Of A Word That "Fits" The Sentence.
Example: Crestfallen by having done poorly on the GRE, Susan began to question her abilities. Her self-confidence was ____________.
A. appeased
B. destroyed
C. placated
D. elevated
E. sustained
If somebody is crestfallen (despairing) and has begun to question herself, then her self-confidence would be destroyed. Hence, the answer is (B).

Transitional Words:

Be alert to transitional words. Transitional words tell you what is coming up. They indicate that the author is now going to draw a contrast with something stated previously, or support something stated previously. 

i. Contrast Indicators:

To contrast two things is to point out how they differ. In this type of sentence completion problem, we look for a word that has the opposite meaning (an antonym) of some key word or phrase in the sentence.

Following are some of the most common contrast indicators:But
Yet
Despite
Although
However
Nevertheless

Example: Although the warring parties had settled a number of disputes, past experience made them _________  to express optimism that the talks would be a success.
A. rash
B. ambivalent
C. scornful
D. overjoyed
E. reticent
"Although" sets up a contrast between what has occurred--success on some issues--and what can be expected to occur--success for the whole talks. Hence, the parties are reluctant to express optimism. The common word "reluctant" is not offered as an answer-choice, but a synonym--reticent--is. The answer is (E).

ii. Support Indicators:

Supporting words support or further explain what has already been said. These words often introduce synonyms for words elsewhere in the sentence.

Following are some common supporting words:
And
Also
Furthermore
Likewise
In Addition
For

Example: Davis is an opprobrious and ________  speaker, equally caustic towards friend or foe--a true curmudgeon.
A. lofty
B. vituperative
C. unstinting
D. retiring
E. laudatory

"And" in the sentence indicates that the missing adjective is similar in meaning to "opprobrious," which is very negative. Now, vituperative--the only negative word--means "abusive." Hence, the answer is (B).

iii. Cause And Effect Indicators:

These words indicate that one thing causes another to occur.

Some of the most common cause and effect indicators are
Because
For
Thus
Hence
Therefore
If , Then .

Example: Because the House has the votes to override a presidential veto, the President has no choice but to ________.
A. object
B. abdicate
C. abstain
D. capitulate
E. compromise

Since the House has the votes to pass the bill or motion, the President would be wise to compromise and make the best of the situation. The answer is (E). 

Punctuation:

Whenever the punctuation "," (comma) appears, followed by a blank in between two sentences, then it means that the synonym of the phrase/word before "," is the meaning of the blank. In simple words, when you find ',' followed by a blank then find the synonym of the word before ',' and check the options to match the synonym of the word.

In the same way, when you find ":"( colon) or ";"( semi-colon) in the sentence, they will indicate that the idea coming up is merely an explanation of the earlier idea. So, simply find the synonym of the word/phrase before the punctuation and fill in the blank with the synonym from the options given.

Positive/Negative Flow:

When you read the sentence, you have to look out for adjectives/adverbs which tell you the idea of the sentence. After finding these adjectives/adverbs, you need to find out if the idea of the sentence is positive/negative. All the negative ideas may be a "bad word/bad phrase" or any term which has no/none/not... in it.
You need to just go on marking the words with +/- and keep on doing till the end of the sentence. Then you need to use the punctuations/conjunctions clue which would break the sentence into 2/3 parts. After that you need to compare the +/- signs on both sides and enter the desired sign in the blank. In simple words, if the flow of the first part of the sentence is positive and the second part is negative, then the blank must be negative to even the flow of the sentence. This would solve the sentence completion question without even understanding the question.

Example: Because he did not want to appear_______, the junior executive refused to dispute the board's decision, in spite of his belief that the decision would impair employee morale.

A. contentious
B. indecisive
C. solicitous
D. overzealous
E. steadfast

Explanation: (C) and (E) are gone because they're positive words. .(B)doesn't work because the clue is "refused to dispute." That doesn't work with indecisive. For the same reason,(D) doesn't work either. So the best answer is option A.

Process of Elimination(POE):

You can easily eliminate all the options that are definitely wrong or are eliminated through the positive/negative flow. Suppose if you have a blank in the sentence for which the answer is positive, then you can eliminate all the options which are negative. In this way you can eliminate options and have very less options remaining. The probability of you getting right answer from 2 options is much higher than you getting right from 5 options.